Data compression for speckle correlation interferometry temporal fringe pattern analysis

Temporal fringe pattern analysis is gaining prominence in speckle correlation interferometry, in particular for transient phenomena studies. This form of analysis, nevertheless, necessitates large data storage. Current compression schemes do not facilitate efficient data retrieval and may even result in important data loss. We describe a novel compression scheme that does not result in crucial data loss and allows for the efficient retrieval of data for temporal fringe analysis. In sample tests with digital speckle interferometry on fringe patterns of a plate and of a cantilever beam subjected to temporal phase and load evolution, respectively, we achieved a compression ratio of 1.6 without filtering out any data from discontinuous and low fringe modulation spatial points. By eliminating 38% of the data from discontinuous and low fringe modulation spatial points, we attained a significant compression ratio of 2.4.